Following the debate, Al Jazeera spoke with three experts - two speechwriters and a body language specialist - to assess the candidates' performance - and they were all eager to point out the uncharted territory this election cycle has presented.

"Never has there been such a stark difference between the candidates and characters on offer," said Simon Lancaster, a London-based speechwriter, who has worked with some of the UK's top politicians.

Clinton's performance

And it was Clinton's ability to remain unflustered that led pundits to label her as the stronger candidate after the debate.

"The short answer is, she cleaned his clock," said Paul Orzulak, who was a speechwriter for Bill Clinton, the former US president and husband of Hillary. "Nothing that [Trump] said took her off her game. From the very first exchange she baited him."

Similarly, Chris Ulrich, body-language expert and former policy adviser to Vice President Al Gore, said: "[Clinton] came to play tonight, she brought her A-game, she was polished."

Much of this was helped by her physical gestures, according to Ulrich.

The Democratic nominee used wide-open hand movements, a sign of compassion and authority.

Furthermore, she smiled a lot, particularly when being attacked, an expression of her assuredness and confidence, Ulrich said.

In comparison to Trump, Clinton's language was much more "low key", according to Lancaster.

Clinton: 'When they go low, we go high'

"Never one for great rhetorical flourish, she hit her stride speaking as an economist about 'steady, sustained and secure growth' and 'Trumped-up trickle-down economics'. Her best soundbite was 'when they go low, we go high', although the trouble was she was quoting Michelle Obama," Lancaster told Al Jazeera.

Overall, she was prepared, said Ulrich.

"She knew how to handle the different types of Donald Trump."

Trump's performance

Trump has always been the better orator, according to Lancaster.

"He spoke in hyperbolic and emotive terms about businesses 'fleeing the country', jobs 'being stolen from us', immigrants 'pouring in', our country being used 'as a piggy bank', how 'we have to knock the hell out of ISIS [the Islamic State of Iraq and the Levant, or ISIL].'”

However, he faltered in much of the debate, according to Orzulak, who said that as the discourse developed, "[Trump] seemed like a guy in a bar who'd had too many drinks and was trying to win an argument".

Trump interrupts Clinton

The experts all referred to the way in which Trump interjected during Clinton's arguments.

"All the times he interrupted her and tried to speak over her, it just enforced his lack of respect for women," Orzulak said.

Moreover, Ulrich said that these interruptions were a sign of Trump's anxiety.

"His voice was low, respectable to start with ... but he allowed himself to get rattled, constantly interrupting Hillary," Ulrich explained, adding that the Republican nominee showed signs of uneasiness as "he would lick his lips and kept grabbing his water".

At one point during the debate, when Clinton accused Trump of not paying federal taxes, the Republican nominee lowered to the microphone and said: "That makes me smart" - and that was Trump's major mistake in the debate, according to Orzulak.

"It astonishes me that he would defend himself in the moment against not paying federal taxes ... I think that will go down as one of the dumbest answers in the history of presidential debates."

According to Lancaster, Clinton did slightly better than most people expected, while Trump did slightly worse.

"The environment favoured Clinton. The muted audience put a focus on argument, in which she excelled ... Trump seemed bare without the usual roars of approval which punctuate his rallies."

Overall, both candidates will have looked presidential to their core audiences, said Lancaster.

"Hillary's composure, her detailed policy prescriptions ... will have spoken to the more intellectual, thoughtful voters. Trump's volatile and emotional outbursts, his no-nonsense plain-speaking approach - that will have spoken to those who are angry, feeling a sense of injustice, impatient for change … still everything for both candidates to play for."